1. Field of the Invention
This invention relates generally to a production cutting apparatus and more particularly to a cutting apparatus for cutting living plant materials.
2. Description of Prior Art
The cutting of green plant material presents certain special difficulties. For example, in preparing tobacco for use in the making of cigarettes, great care must be exercised when cutting tobacco leaves that are living. The leaves are wet and green and can have a moisture content of 80 percent or more. In addition, green leaves are fragile and come in non-uniform dimensions. The use of loading hoppers or coil feed systems such as employed in the prior art for dried tobacco is not suitable because of the fragile and living nature of green leaves. As leaves are fed into the loading hoppers, the bottom leaves are crushed. With dry tobacco leaves, this crushing force is acceptable because there are no living cells or essential fluids in the leaf. However, green tobacco leaves contain living cells and essential fluids, which will flow upon crushing destroying the high quality of the leaves. Additionally, mechanical damage such as tearing of the leaf can occur by being crushed in a loading hopper. The mechanical damage will adversely affect the ability to obtain clean cuts from the green tobacco leaves necessary for the proper curing of the leaves for use in cigarettes.
Coil feed systems similarly damage the green tobacco. Coil feed systems, which are described below in further detail, exert sharp local pressures at the various turns or coils in the feed system. These sharp local pressure points cause the living cells and essential fluids of green tobacco leaves to flow. Additionally, leaves going through the coil feed system tend to become frayed and otherwise mechanically damaged, thereby adversely affecting their quality.
If the leaf cells are damaged, leaves will turn dark brown rather than the preferred yellow and orange after aging. This discoloring of the leaves, lowers the quality of the leaves dramatically. Thus, a high quality green leaf may be lowered in quality and no longer suitable for making quality cigarettes because it has turned dark brown or has other discoloration present.
Similarly, the tearing of leaves will lower quality. In order to make cigarettes using tobacco leaves aged after cutting, the leaves must have clean cuts of generally uniform and predetermined strip widths. When the leaf is torn or otherwise damaged, cigarette production from such leaves is adversely affected.
It is also important to have a clean cut of the leaves so that the cells of the leaves are not damaged in any way. Damaging the cells of the leaves results in the lowering of quality of the tobacco leaves. Cell damage causes the juices to flow and discoloration as well as mechanical damage to the leaves.
Presently, tobacco leaves are cut manually after they have been specially bundled and folded. The bundles must be folded by a skilled laborer and in a certain fashion so that when the leaves are cut they are cut cleanly and in a generally uniform manner. It will be appreciated that there is considerable skill required, not only in the folding of the bundles, but also in the cutting of the bundles. The skilled artisans and the amount of time involved in production causes these cigarettes to be quite costly, presently. To date, no non-manual cutting apparatus has been developed which cuts uniform strip widths without damaging the fragile green tobacco leaves.
It has been long recognized that there are certain difficulties in cutting tobacco leaves. For example, in U.S. Pat. No. 840,416 issued in 1907, it was found desirable to have a mechanical device which cut tobacco leaves from a hopper above a conveyor and which then fed the tobacco through a series of rollers to a cutting knife. This is acceptable for dry tobacco leaves because they contain no living cells and essential fluids, so pressure points and even crushing do not adversely affect the quality of the leaves. However, green tobacco leaves which do contain living cells and essential fluids are quite different as pointed out above. Any attempt to feed green tobacco leaves through a series of rollers would result in severe mechanical damage and cause the living fluids to flow dramatically lowering the quality of the leaf and adversely affecting cigarette production.
Another patent, namely, U.S. Pat. No. 480,638, discloses the problem of clogging cutting blades.
Other prior devices, namely, U.S. Pat. No. 995,465 which shows a machine for dividing a ribbon into pieces of uniform length which has upper and lower drive belts for feeding and U.S. Pat. No. 840,416 which provides fixed rollers for feeding tobacco are not suitable for cutting green tobacco leaves. Each of these above references are inflexibly configured which could result in pressure that will damage or tear the green tobacco leaves.
No prior cutting device has been found which will allow the continuous loading of living green leaves onto a feed apparatus, where the leaves will be cut into generally uniform strips with each strip having a clean cut so that a minimum of damage to the living plant material occurs. Accordingly, there is a need for a machine that will produce a consistent cut of green leaves at a predetermined width, without requiring skillful folding of the leaves, to increase production rate for cutting.